Escalation of negative social exchange: Reflexive punishment or deliberative deterrence?

Negative escalation of social exchange exacts significant costs on both individuals and society. Instead of in-kind reciprocity—an eye for an eye—negative reciprocity may escalate, taking two eyes for an eye. We tested two competing mechanisms for negative escalation using a modified dictator game that reliably produces escalating reciprocity to others' negative actions but not to positive actions. According to one mechanism, escalation is...